AGPRate and PowerStates INFO

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This is a generic info! (they don't mean the ReqAgpRate setting in the inf)

AgpSetRate: This function is available in Microsoft Windows XP and later.

The transfer rate set by the AgpSetRate function is persistent across changes in power state. The video miniport driver does not have to reset the AGP transfer rate when it changes from a low power state to a full power state. For information about change of power state, see HwVidSetPowerState.

The AgpSetRate function can be used to change an AGP chipset's data transfer rate to any of the rates shown in the preceding table, as long as that transfer rate has not been explicitly eliminated in the INF file that loaded the display driver.

PowerStates:

Specifies the power management state to be set or queried. This member can be one of the following values in the VIDEO_POWER_STATE enumeration:

VideoPowerOn

The monitor and graphics adapter are both fully powered on and operational.

VideoPowerStandBy

The monitor is running at a reduced power level that requires a short recovery time to VideoPowerOn. The graphics adapter is powered on (registers are still active and video memory is refreshed); however, clocks might be lost.

VideoPowerSuspend

The monitor is running at a substantially reduced power level that requires a possibly longer recovery time than VideoPowerStandBy to VideoPowerOn. The graphics adapter is off.

VideoPowerOff

The monitor and graphics adapter are both off, consuming no power at all.

VideoPowerHibernate

The monitor and graphics adapter are both fully powered on and operational.

VideoPowerHibernate is provided to the miniport driver as notification only. The miniport driver's HwVidSetPowerState function must leave the monitor and graphics adapter fully powered on and operational. For all other states, the miniport driver must put the device into the specified power state.

A driver will always enter all other power states from the VideoPowerOn state. For example, a driver will not move directly to VideoPowerHibernate from VideoPowerOff; it will always go from VideoPowerHibernate to VideoPowerOn and then to VideoPowerOff.